I recently downloaded Dolphin 5.0 64 bit and ran across some issues with it using my second GPU on my HP laptop. The fact of the matter was it just couldn't detect it in the Video Configuration setting. Because Dolphin wasn't utilizing my Discrete GPU it was stuck with the Integrated GPU which wasn't satisfactory enough for the game I was playing. I was getting less than 30 FPS during gameplay with OpenGL and DirectX turned on and the lag was noticeable enough that I didn't want to play my games. I searched these forums and saw that someone said that even if you have the Discrete GPU selected on your computer that its normal Dolphin wont detect it. And Even though its displaying its using the Integrated GPU its actually using the Discrete as long as you have it selected in your GPU's program manager (Which in my case was Catalyst Control Center). To me that didn't sound right at all so I did some research and this is what I found.

With OpenGL Applications certain HP Laptop models cannot use Discrete GPU with Intel+AMD Switchable Graphics. I noticed the same thing with DirectX Applications. The only remedy to this is to change your GPU setting from Dynamic to Fixed in the BIOS settings and only then can you utilize OpenGL and DirectX Applications with your Discrete GPU.

So what I did was change my BIOS to Fixed GPU and selected DirectX and my discrete GPU was appearing. I ticked V-Sync and Im playing a game that was previously running at 20-30 FPS at a whopping 60 FPS .
Happy Gaming Guys

If anyone has any questions Please ask and we might be able to figure it out together .